The present invention relates to an opto-mechanical on/off switch, and more particularly to such a switch which is monolithically fabricated and magnetically actuatable and to systems using such a switch.
The common electrical reed relay is an example of an electro-mechanical on/off switch which can be operated by an electromagnetic field so that it either conducts or does not conduct electricity. An opto-mechanical on/off switch is similar to an electrical reed relay but, depending on whether it is actuated or not, either enables or disables an optical transmission rather than an electrical transmission. The on/off switch may act as a single pole, single throw switch or as a modulator.
A magnetically-actuatable opto-mechanical on/off switch, like the common electrical reed relay, has a variety of different applications. For example, it may be used as a liquid level sensor operated by a float magnet for level detection, as a modulator to enable detection of very small optical signals by synchronous demodulation, as an optical pick-off in a flowmeter that uses magnetic energy to communicate the position of an internal flowmeter part to the optical pick-off, etc.
Currently available products use a mechanical approach to electrically control optical switches which is similar to that used for electrically controlled reed relays--that is, an electric coil moves a mechanical part which carries an input optical fiber to a position of transmission with respect to one or another output fibers. Such prior art electrically controlled optical switches are typically of substantial mass. Since such discrete optical switchers must typically be fabricated separately (i.e., one switch at a time), the switches, and particularly arrays of these switches, tend to be expensive to manufacture. Thus, the need remains for an economical optical switch which is of smaller mass than the usual prior art relay parts so that switching can be performed with significantly less energy and/or in significantly less time.
Accordingly, it is an object of the present invention to Provide a magnetically-actuatable opto-mechanical on/off switch.
Another object is to provide such a switch which is of smaller mass than comparable prior art optical switches so that switching can be performed with significantly less energy and/or in significantly less time.
A further object is to provide a system and device containing a plurality of such switches, optionally monolithically fabricated on a single substrate.
It is also an object of the present invention to provide such switches, systems and devices which are economical to manufacture and inexpensive to maintain.